Redundancy of 4.8 for a 74% complete shell (if I understand which
shell these stats are for) suggests you have assumed too much symmetry
and are rejecting a lot of reflections during scaling. Is this the
case? The I/sigma suggests you could drop the symmetry and re-scale
without losing a lot of data if this is the case.
On Mar 17, 2008, at 4:03 AM, Melody Lin wrote:
well, redundancy for the highest shell is 4.8, I/sigma is 3, Rmerge
for overall is 0.08 for highest shell is 0.336. I/sigma and Rmerge
don't seem quite nice...
thanks.
On Mon, Mar 17, 2008 at 11:51 AM, Partha Chakrabarti
<[EMAIL PROTECTED]> wrote:
Hi Melody,
There was a nice discussion in this year's ccp4 study weekend. In
general, one needs to consider several factors.. If you were at 3A, or
low symmetry, you would of course try to get the maximum out of it, on
the other hand, there are requirements for experimental phasing.. in
general, judge it from:
1. Completeness
2. Redundancy
3. I / Sigma
4. R merge statistics
Not just one of them. If you are pushing it too far, you will see the
effect in later refinement step..
With 74% completeness, how does the other parameters look like?
HTH, Partha
On Mon, Mar 17, 2008 at 10:06 AM, Melody Lin <[EMAIL PROTECTED]>
wrote:
> Hi all,
>
> I have always been wondering... for a data set diffracting to say
2.15
> Angstrom but in the highest resolution shell (2.25-2.15) the
completeness is
> 74%, should I use merge all the data and call it a 2.15 A dataset
or I
> should cut the data set to say 2.25 A where the highest resolution
shell has
> better completeness (>85%)? What is an acceptable completeness
value for the
> highest resolution shell?
>
> Thank you.
>
> Best,
> Melody
>
--
MRC National Institute for Medical Research
Division of Molecular Structure
The Ridgeway, NW7 1AA, UK
Email: [EMAIL PROTECTED]
Phone: + 44 208 816 2515
--
James Stroud
UCLA-DOE Institute for Genomics and Proteomics
Box 951570
Los Angeles, CA 90095
http://www.jamesstroud.com
